functional form that provided the best fit for all five outcomes. The integrated exposure–response curve was then used to generate effect sizes specific to the amount of ambient particulate matter smaller than 2·5 µm for each population. For ischaemic heart disease and stroke, evidence shows that household air pollution affects intermediate outcomes, such as blood pressure,139 but not clinical events. For acute lower respiratory tract infection, the integrated exposure– response curve enabled us to extrapolate beyond the partial exposure–response measured in the RESPIRE trial.140 For effects of household air pollution on chronic obstructive pulmonary disease and lung cancer we use the effect size based on new systematic reviews and meta-analyses.
